The present invention relates to a method for damping and/or amplifying a sound introduced into a passenger compartment of a motor vehicle, in particular an electrically driven motor vehicle, said sound being generated by a sound source arranged outside of the passenger compartment
The present invention further relates to a device for damping and/or amplifying a sound introduced into a passenger compartment of a motor vehicle, in particular an electrically driven motor vehicle.
In the field of motor vehicle drive technology, it is generally known to use one or a plurality of electrical machines as the sole drive or together with a drive motor of another type (hybrid drive). Hybrid drives consist of a combination of an internal combustion engine and at least one electrical machine as well as the associated energy stores in the form of a fuel tank and a battery.
One characteristic of the purely electrically driven motor vehicles is that said vehicles generate a substantially quieter driving and operating noise than conventionally driven motor vehicles. They therefore generate only a very quiet engine noise. Intake, combustion or exhaust noises do not exist on account of the design principle. This also similarly applies to motor vehicles comprising a hybrid drive, in the event said vehicles (e.g. at low speeds) are operated in the purely electrical driving mode. On the one hand, said quiet driving and operating noises are very desirable in the sense of a reduced road traffic noise. The quality of life is thereby improved in large cities, in particular along the heavily traveled roads. On the other hand, vehicle noise does serve as a warning signal for an approaching vehicle. The exterior sound of electric vehicles is however so low at low speeds that the vehicles can no longer be noticed by, in particular, visually impaired people or in cases of reduced perception and could thus result in vehicle-person accidents.
Systems for installation in electric vehicles are currently being discussed throughout the world, which emit via a loudspeaker system an additional electronically generated sound at low speeds in order to warn road users in the proximity, such as, e.g., bicyclists or pedestrians, of the approaching vehicle. In order to actively generate an exterior sound, other systems are however also conceivable, such as the use of other oscillation generators or the targeted actuation of the electric machine or of ancillary units in the motor vehicle.
In order to ensure traffic safety, regulations or guidelines with regard to the active generation of exterior sound in the low speed range of electric vehicles are furthermore being developed, said regulations or guidelines being to ensure a perceptibility of said vehicles by pedestrians, bicyclists or other road users.
On the other hand, the quiet internal sound when driving in the electrical mode contributes substantially to the feeling of comfort of the driver. It is to be expected that this comfort aspect is seen as a particular advantage with respect to diesel/gas vehicles from the point of view of the vehicle manufacturer. This applies particularly to low speed ranges. At high speeds, rolling and wind noises can also be heard in the interior of the vehicle.
It is therefore desirable to simultaneously shield the vehicle interior with respect to measures taken to actively generate exterior sound in order to preserve the driving comfort.